1. Field of the Invention
The invention relates to the field of tools for removing a vehicle tire from a wheel rim, and in particular to a manual pry tool for reaching and pulling free both beads of a truck tire from one side of the rim.
2. Prior Art
Various tools for removing a tire from a wheel rim are known. Such tools generally comprise an elongated pry bar which has a handle end to be gripped by a user, and a flattened tool end for insertion between one bead of the tire and the wheel rim. The beads of the tire normally reside between flanges of the wheel rim and the beads must be moved axially outwardly over the rim flange to remove the tire from the rim. After the tool end is inserted between the tire and the wheel rim, the user applies pressure to the handle end, using the tool as a lever with the wheel rim as a fulcrum, in order to pry a short length of the tire bead (which is of slightly smaller circumference than the wheel rim but can be resiliently stretched) beyond the flange of the wheel rim. The process is repeated in successive stages, often by using two or three pry tools around the periphery of the wheel rim until the tire bead is more than halfway passed over the rim, whereupon the resilience of the bead assists in drawing the remainder of the bead to the outside, and the bead can be completely passed over the wheel rim flange. Alternatively, after a length of the tire bead has been pried beyond the rim flange, a machine may be utilized for sliding the tool end circumferentially around the periphery of the wheel rim flange whereby the tire bead is pulled over the rim flange in a continuous motion. In either case, the tool end of the removal device may also have one or more appendages for contacting the wheel rim or tire in a beneficial manner during the removal operation.
In U.S. Pat. No. 2,188,211 to Tilson there is disclosed a simple removal tool wherein the tool end is a flattened bar which is suitably curved to conform to the inside of a wheel rim flange. A user inserts the tool end between the tire and the rim flange, and applies pressure on a handle end of the tool in order to pull a portion of the tire bead over the rim flange. The bead is pulled radially outwardly of the rim as well as axially over the rim flange, in a prying motion. The user must hold the starting portion and lift successive portions of the tire bead beyond the rim flange in sequence proceeding around the periphery of the wheel rim in order to pass the entire bead over the flange. This is done for each bead to remove the tire from the rim.
U.S. Pat. No. 2,294,271 -- Bethard and U.S. Pat. No. 2,399,146 -- Schumann disclose tools for loosening a tire bead from a wheel rim. The tools include a projecting portion for insertion between the tire and the rim flange. The tools are intended for loosening large size truck or tractor tires which not only are difficult due to their size, but also may be stuck to the rim because of rust or dirt. Neither Bethard nor Schumann teach a tool for passing a tire bead over a rim flange. Similarly, U.S. Pat. No. 2,565,216 -- Fox discloses a tool for loosening a tire from a wheel rim, but Fox does not disclose any tool or method for lifting the tire bead over the rim flange.
U.S. Pat. No. 4,919,184 -- du Quesne discloses a tool for removing a tire of the type wherein the tire bead is mounted over the outside of the rim flange. The tool is not useful for removing a conventional tire wherein the tire bead is mounted inside of and between the two opposite flanges of a wheel rim.
U.S. Pat. No. 4,527,607 -- Gaither discloses a tire removal tool having an arcuate flange insertable between a tire bead and wheel rim, and a plurality of roller members at the outer end of the arcuate flange for engaging the inner wall of the tire. The tool further has an arm member with a second plurality of rollers at its end for engaging the wheel rim. The arm member extends at a planar angle with respect to the body of the tool. Gaither discloses using the tool to remove an upper tire bead from the wheel rim when the tire is disposed horizontally on the ground. This is accomplished by inserting a separate bar into the tool for providing leverage, and pulling back on the bar to use the rim flange as a fulcrum. Due to the substantial width of the arcuate flange, it is possible to pull the bead over the rim in one lever motion rather than to lift successive segments while advancing the tool circumferentially around the rim. Gaither does not disclose using such a tool to remove a lower tire bead from the wheel rim. The tool as taught by Gaither cannot be effectively used to remove the lower tire bead because the arm member, which extends at a planar angle with respect to the body of the tool, interferes with the wheel rim and limits the depth to which the outer end of the arcuate flange can be inserted between the tire and the wheel rim in an effort to engage the lower bead. Gather teaches a different form of tool for the lower bead which requires that the user force a short plate through a gap between both beads and the rim, which plate can receive the separate bar for forcing the tire fully over the rim flange.
There is a need for a tire removal tool which permits the removal of both the lower and the upper tire beads from the wheel rim in successive operations, in a manner that allows single lever motions to pull free the first bead and the second bead in sequence.